The present invention relates to a work vehicle.
In conventional work vehicles, such as a tractor and a wheel loader, an engine is mounted on a front portion of a vehicle body frame, a transmission case is coupled to a rear portion of the vehicle body frame, and a traveling machine body is supported by front and rear traveling units. For example, the transmission case incorporates a traveling transmission gear mechanism, a differential gear mechanism, a PTO transmission gear mechanism, and the like. Driving force from the engine on the front side is transmitted to the transmission case on the rear side, and is transmitted to at least the left and right rear traveling units from the differential gear mechanism in the transmission case. The driving force is further transmitted to a working unit, such as a rotary tiller, from the PTO transmission gear mechanism in the transmission case (see, for example Japanese Unexamined Patent Application Publication No. 2010-52734).
In a work vehicle in Japanese Unexamined Patent Application Publication No. 2010-52734, an inline hydraulic continuously variable transmission is assembled in a transmission case. The hydraulic continuously variable transmission includes: a hydraulic pump unit that receives driving force from an engine via an input shaft; and a hydraulic motor unit that transmits a shifted output to rear traveling units and the like via an output shaft. The input shaft and the output shaft are coaxially positioned to form a double shaft. A cylinder block is fit on and integrally rotates with the input shaft. The hydraulic pump unit and the hydraulic motor unit are fit on the input shaft at portions respectively on one side and the other side of the cylinder block.
Some work vehicles include: a forward and backward switching mechanism that switches an output from the hydraulic continuously variable transmission between normal rotation and reverse rotation directions; a double speed driving mechanism that increases the rotation speed of left and right traveling units when a traveling machine body makes a turn while traveling forward; and a brake mechanism that is configured to automatically put a brake to a rear traveling unit on an inner side of the turn when the double speed driving mechanism is operating (see, for example, Japanese Unexamined Patent Application Publication No. H10-81255). In the work vehicle of this type, hydraulic oil from a hydraulic pressure source is supplied to hydraulic devices (hydraulic clutches, hydraulic cylinders, and the like) for the hydraulic continuously variable transmission, the forward and backward switching mechanism, the double speed driving mechanism, the brake mechanism, and the like, so that the mechanisms can operate.